Kinetics and Mechanism for the UV-Visible Photolysis Ferrioxalate Complexes in the Absence and Presence of Oxygen, in Aqueous Solutions.

In this work, the UV-Visible photolysis aqueous ferrioxalate complexes has been studied kinetically and mechanistically, in the absence and presence of molecular oxygen.

Ortho-phenylene diamine Study of kinetic by catalase

Catalase enzyme has two functions, first is catalytic and destroyed with high temperature. The second function oxidic , increasing with high temperature. The catalase enzyme effects on the substrate of ortho – phenylene diamine turning it into aromatic cancerogenus azo compounds organic acids such as, benzoic acid, salicylic acid and ascorbic acid inhibit the effect of catalase enzyme substrate ortho – phenylene diamine. The inhibition is competitive when the benzoic acid and salicylic acid effects , while the inhibition is non competitive when the ascorbic acid effect.

Determination Some Kinetic Parameters for Thermal and Catalytic Cracking of The Mixed of Polyethylene and Polypropylene

Some kinetic parameters have been determined in this work for thermal and catalytic cracking of the mixed of polyethylene and polypropylene using batch method. The cracking reaction was carried out at different temperature 470,490 and 510oC under atmospheric pressure. The mass of products (liquid and gas fractions) were determined and used to plot the curves of the thermal and catalytic decomposition. We used two types of catalysts: Syrian natural Zeolite and the same after loading with sulfate ions using impregnation method. The thermal cracking has a long time and has firs-pseud order reaction. While in the case of catalytic process we note that the reaction finished in the short time and the process is the Zero-pseud order reaction. The rate of the cracking increased very much, the rate constant was k1=0.0032.min-1 in the thermal cracking at 4700C and ko=0.111.min-1 in the case of catalytic cracking in presence of Z catalyst and ko= 0.206 min-1 in presence of 15-SO4 2-/Z as catalytic at the same temperature. In the other hand activation energy was 208.7 kj/mol in the thermal process and decreased to 116.6 kj/mol at Z catalytic presence and to 87.3 kj/mol at 15-SO4 2-/Z catalytic presence.

A comparative study of caffeine release from carbopol gels and emulgels

The objective of this study was to study and to analyze caffeine release from gel and emulgel prepared from carbopol. The properties of the preparations were determined (e.g. visual inspection, pH test, spreadability and in vitro release). The mechanisms of caffeine release were analyzed according to zero and first orders, and to Higuchi and Korsmeyer- Peppas models. Results were analyzed statistically using student t-test. The gels were transparent while emulgels were creamy, white and smooth. pH values were suitable for dermal application and spreadability was not changed in both cases. On the other hand, accumulated released amount of caffeine was decreased from emulgel in comparison with the gel. The release pattern was in accordance with Higuchi equation and n value referred that the diffusion was the main mechanism of release from the gel while the relaxation and the erosion contributed importantly in the release of suspended caffeine from emulgel.

Ecological Study on the Gastropod Valvatasaulcyi in One Station of the Lower Reach of AlSanawbar River-Lattakia

Three sampling stations were chosen along the lower reach section of AlSanawbarriver (Lattakia-Syria). In these stations, the freshwater molluscs were studied, environmentally and taxonomically, during the period 4/3/2012 – 4/8/2013. In this research, I present the results of the environmental study on the Gastropod Valvatasaulcyiwhich was more abundant in the 3rd station; 5km of the estuary. Ten mollusc species were identified; 8 belonging to Gastropoda (4 of Prosobranchia & 4 of Pulmonata) and 2 belonging to Bivalvia. The chemical and physical properties of the water in the 3rd station were studied and the work was concentrated on Valvatasaulcyipopulation and structure, where samples were collected bimonthly during Spring, summer & autumn and monthly during winter. It was shown that reproduction of such species is continuous along the year, with 2 reproduction beaks: the more important one is spring beak and the less important one is autumn beak. The population structure of the species was studied: shell dimensions were measured and the relationships were studied between height growth and breadth growth of the shell, and between the breadth growth and dry weight of the individual ….

Preparatin of polyamide (dimeric acid C36 with 1,5 -diaminopentane) and study of catalystes effect on kinetics of the reaction

Fattypolyamide was prepared by reaction of (1,5-Diamino pentane) with dimeric fatty acid C36 in molten state. The reaction was performed at 110 C˚ without catalyst, then with (Phosphoric acid, Sulphoric acid and Manganese dioxides). The Kinetic study was carried out on the reaction and followed by determining the acid value of the product. The polyamidation reaction was found to be on the overall a second order up to 59% conversion. Then the reaction order changes. We found that the Catalyst increases the velocity of the reaction with manganese dioxides the best Catalyst. The Degree of Polymerization, Number Average Molecular Weight and Weight Average Molecular Weight have been calculated during different times. The relationships between Degree of Polymerization and Number Average Molecular Weight, Weight Average Molecular Weight with times are linear until 59%conversion at 110˚C with used catalysts. The highest (N.A.M.W) and (W.A.M.W) was accomplished with the Catalyst MnO2.

Kinetics of reaction dimer fatty acid C36 with 1,9 diamino nonane and determination of thermodynamic constants by use of thermogravimetric analysis tga, and rheological constants for the resulted polyamide

Study the kinetics degradation of poly (dimeric acid C36 with 1.9 – diamino nonane) was carried out by thermal analysis (TGA), and thermodynamic and equilibrium constants have been defined, moreover, study the kinetics of reaction between 1.9 – diamino nonane and dimer fatty acid C36 was carried out in molten state, the reaction was performed at 160 ºC, the acid value, and percentage of carboxylic functions of the product were determined. The polyamidation reaction was found to be of overall second order until conversion of 97% at 160 ºC, then the order of reaction changes.

Study The Influence Of Reacted Aliphatic Amine Series Length On Its Kinetic Reaction With Dimeric Fatty Acid C36 And Properties Of Resulted Polyamide

Kinetic studies were carried out on the reaction between dimeric fatty acid C36 with 1.3 Diamino propane and 1.4 Diamino butane and 1.6 Diamino hexane and 1.8 Diamino octane in molten phase. The reaction was performed at 145ºC. The polyamidation reaction was found to be on the overall a second order up to 83% conversion for reaction dimeric fatty acid C36 with 1.3 Diamino propane and 86% conversion for reaction dimeric fatty acid C36 with 1.4 Diamino butane and 87% conversion for reaction dimeric fatty acid C36 with 1.6 Diamino hexane and 1.8 Diamino octane then the reaction order changes to the third order above last conversion. The degree of polymerization,number average molecular weight and weight average molecular weight have been calculated during different times. Their relationships with the times are linear until last conversion. The melting point and thermodynamic constants for melting are determined by use of differential scanning calorimetry DSC. The melting point and thermodynamic constants increase by increasing the length of reacted amine series.

Kinetics Of Reaction Of 1,10- Decanedioland Dimeric Fatty Acid C36

Kinetic studies were carried out on the reaction between 1,10– Decanedioland dimeric fatty acid C36 in melt phase. The reaction was performed at 140, 150, 160, 170, and 185ºC and followed by determining the acid value of the product.

Kinetics Of Reaction Of 2-Methyl 1,5 diaminopentane and Dimeric Fatty Acids

Kinetic studies were carried out on the reaction between 2-Methyl 1,5 diaminopentane and dimeric fatty acids in melt phase. The reaction was performed at 113, 130, 140, 155, and 164 ºC and followed by determining the acid value of the product .The polyamidation reaction was found to be of overall second order with an activation energy of 45.48 k cal⁄g mol up to (52, 57, 79, 80, 86)% conversion at (113, 130, 140, 155, 164) ºC and overall third order with an activation energy of 43.73 k cal⁄g mol above (52, 57, 79, 80, 86)% conversion at (113, 130, 140, 155, 164) ºC.